Acquisitions/Dispositions - Additional Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Business Acquisition [Line Items]
Total assets		$ 215,543	$ 205,962
Total liabilities		191,263	180,808
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		3,420	2,959	[1],[2]	$ 2,830	[3],[4]
Noninterest Expense		5,673	5,764	[1],[2]	5,468	[3],[4]
Proceeds from Divestiture of Businesses		0	261		0
Gain (Loss) on Disposition of Business		0	107		0
Premium Assignment Corporation [Member]
Business Acquisition [Line Items]
Total assets			1,300
Total liabilities			1,200
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest			25		33
Revenues			56		60
Noninterest Expense			31		27
Proceeds from Divestiture of Businesses			261
Gain (Loss) on Disposition of Business			107
Pillar Financial [Member]
Business Combinations [Abstract]
Indefinite-lived Intangible Assets Acquired	[5]				13
Business Acquisition [Line Items]
Business Combination, Consideration Transferred					(197)
Wholesale [Member]
Business Acquisition [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		2,024	1,978	[1],[2]	1,484	[3],[4]
Noninterest Expense		$ 1,720	$ 1,727	[1],[2]	$ 1,507	[3],[4]

[1] During the second quarter of 2018, certain of the Company's business banking clients were transferred from the Wholesale business segment to the Consumer business segment. For all periods prior to the second quarter of 2018, the corresponding financial results have been transferred to the Consumer business segment for comparability purposes.

[2] During the fourth quarter of 2017, the Company sold PAC, the results of which were previously reported within the Wholesale business segment. For all periods prior to January 1, 2018, PAC's financial results, including the gain on sale, have been transferred to Corporate Other for enhanced comparability of the Wholesale business segment excluding PAC.

[3] During the second quarter of 2018, certain of the Company's business banking clients were transferred from the Wholesale business segment to the Consumer business segment. For all periods prior to the second quarter of 2018, the corresponding financial results have been transferred to the Consumer business segment for comparability purposes.

[4] During the fourth quarter of 2017, the Company sold PAC, the results of which were previously reported within the Wholesale business segment. For all periods prior to January 1, 2018, PAC's financial results, including the gain on sale, have been transferred to Corporate Other for enhanced comparability of the Wholesale business segment excluding PAC.

[5] Does not include $62 million of commercial mortgage servicing rights acquired.